Method of manufacturing a semiconductor element-mounting board

ABSTRACT

A method of manufacturing a semiconductor mounting board includes providing a base member and linear conductive members formed of metallic wires. The conductive members are constructed so that they extend linearly between a semiconductor element-mounting face and a circuit board-mounting face of a base member, and are integrally molded within the base member. For this purpose, a resin material for forming the base member is injected into a mold wherein the conductive members are linearly arranged beforehand.

This application is a Continuation Application of Ser. No. 09/878,419filed Jun. 12, 2001, now abandoned, which is a Divisional Application ofSer. No. 08/890,009, filed Jul. 8, 1997, now U.S. Pat. No. 6,265,673 B1.

BACKGROUND OF THE INVENTION

The present invention relates to a semiconductor element-mounting boardwith a semiconductor mounted thereto by a flip-chip mounting method, anda semiconductor device using the semiconductor element-mounting board.

Along with the current rapid progress changing electronic appliances tobe compact and exhibit high-performance, as represented by portablephones, personal computers, pager units, etc., the number ofsemiconductors used in each electronic circuit has increased. Meanwhile,the electronic circuit comes to use a frequency band as high as 1 GHz,whereby not only the processing speed of an integrated circuit (IC)matters, but the wiring length of the electronic circuit also mattersmuch. The IC is consequently being changed from a package IC to a bareIC and mounted by a flip-chip mounting method, wherein the active sideof the IC faces down and the inactive side faces upward, not by a wirebonding method. In a chip size package (referred to as “CSP”hereinafter) as a typical form of the flip-chip mounting method, thesemiconductor element is first mounted on a special board by theflip-chip mounting method, sealed, and then finally mounted on a printedcircuit board.

A flow of procedures in the aforementioned CSP mounting method and thestructure of the CSP will be described with reference to the drawings.

FIG. 21 shows the structure of the CSP. A semiconductor element-mountingboard 2—called a carrier—onto which a semiconductor element 23 is to bemounted by the flip-chip mounting method is manufactured by layering aplurality of ceramic boards according to the prior art. In the board 2,the semiconductor element 23 is arranged at the side of a semiconductorelement-mounting face 2 a where electrodes 2 c are formed, while aprinted board is disposed at the side of a circuit board-mounting face 2b where bonding lands 18 are formed. An interlayer conduction part 5 isprovided between layers of the semiconductor element-mounting board 2 soas to electrically connect the electrodes 2 c with the bonding lands 18.Projecting electrodes 24 are formed on aluminum pads 23 a of thesemiconductor element 23, and are electrically connected by a conductivepaste 25 with the electrodes 2 c at the semiconductor element-mountingface 2 a of the board 2. The semiconductor element 23 is electricallyconnect to the printed board in this manner. A connected part betweenthe semiconductor element 23 and the semiconductor element-mountingboard 2 is sealed by a sealant 26.

In FIG. 21, a face provided with wirings of the semiconductor element 23faces to the board 2 and therefore this way of mounting is denoted as aflip-(inverted) chip mounting. The semiconductor element-mounting board2 is often formed in a multi-layer structure as indicated in the drawingso as to improve a wiring density through wirings between electrodes ofthe layers. However, this unfortunately increases a total wiring lengthin the semiconductor element-mounting board 2.

The lands 18 are at the circuit board-mounting face 2 b of the board 2are formed larger in diameter than a via hole, thereby to compensate fora positional shift of the via hole. Although the bonding lands are flatin FIG. 21, metallic balls of solder or the like, or long pins are addedto the lands in some cases, respectively called as a ball grid array(BGA) and a pin grid array (PGA).

FIG. 22 shows a process flow of the conventional CSP mounting. In step 1(abbreviated as “S1” in FIG. 22), the projecting electrodes 24, i.e.,bumps, are formed on the aluminum pads 23 a on the active face of thesemiconductor element 23. In step 2, the projecting electrodes 24 areleveled. In step 3, a required amount of the conductive paste 25 istransferred onto the projecting electrodes 24. Then, the semiconductorelement 23 is inverted in step 4 and the projecting electrodes 24 withthe conductive paste 25 are mounted to the electrodes 2 c formed on thesemiconductor element-mounting board 2 in step 5. Thereafter, in orderto prevent the semiconductor element 23 from being shifted or separatedfrom the mounting board 2, the conductive paste 25 is set up in step 6.The sealant 26 is injected between the semiconductor element 23 and themounting board 2 in step 7. When the sealant 26 is set in step 8, theCSP is completed.

The electronic appliances these days are made compact, light-weight andthin through the above-described mounting technique.

The conventional semiconductor element-mounting board 2 hasdisadvantages as follows. While etching is preferred to form a finewiring pattern to the semiconductor element-mounting face 2 a and thecircuit board-mounting face 2 b of the board 2, a special poisonousetching solution would be needed for the etching of the board 2, becausethe conventional mounting board 2 is made of ceramic as mentionedearlier. As such, printing is utilized heretofore to form the wiringpattern on the surfaces of the board. In other words, the wiring patternis difficult to make fine in order to match a pitch of the ICs.Moreover, since the bonding lands 18 larger than the via holes should beformed on the circuit board-mounting face 2 b of the board 2, this makesit hard to satisfy the above fine pitch of the ICs. While the mountingboard 2 is constituted of a plurality of layers and the wiring isprovided between the layers in order to make up the aforementionedimperfect, not-fine wiring pattern, a conduction resistance between thelayers is unfavorably increased. Through holes are also necessary toform the interlayer conduction part 5. Thus the conventionalsemiconductor element-mounting board 2 in a multi-layer structure withthe wiring provided between the layers has a high cost and requires along lead time, while having poor mounting reliability onto the printedboard.

SUMMARY OF THE INVENTION

The present invention is devised to solve the above-describeddisadvantages. The object of the present invention is to provide asemiconductor element-mounting board and a semiconductor device usingthe board which are manufactured inexpensively, shows a low interlayerconduction resistance, fits to multi-pin ICs, has improved mountingreliability onto a printed board, increases productivity and shortens amanufacture lead time.

In accomplishing these and other aspects, according to a first aspect ofthe present invention, there is provided a semiconductorelement-mounting board including a base member which includes asemiconductor element-mounting face to which a semiconductor element ismounted. The semiconductor element is electrically connected by aflip-chip mounting method. The base member also includes a circuitboard-mounting face opposite to the semiconductor element-mounting faceand which is mounted to a circuit board. The base member is formed of anelectrically insulating resin material in one layer.

The semiconductor element-mounting board also includes linear conductivemembers, all of which are nearly orthogonal to the semiconductorelement-mounting face and the circuit board-mounting face. The linearconductive members extend linearly to penetrate to an interior of thebase member thereby to electrically connect the semiconductor elementwith the circuit board.

According to a second aspect of the present invention, there is provideda semiconductor element-mounting board according to the first aspect,wherein the conductive member is formed of a metallic wire.

According to a third aspect of the present invention, there is provideda semiconductor element-mounting board according to the first or secondaspect, wherein the conductive member is formed of any one metalselected from a group consisting of Cu, Au, Al, Ag, Pd, and Pt, or analloy mainly composed of one of the metals.

According to a fourth aspect of the present invention, there is provideda semiconductor element-mounting board according to any one of the firstthrough third aspects, wherein the resin material is a liquid crystalpolymer having a heat resistance of 250° C. or higher and a thermalexpansion coefficient of 15 ppm or lower.

According to a fifth aspect of the present invention, there is provideda semiconductor element-mounting board according to any one of the firstthrough fourth aspects, wherein the conductive member has an end facelocated on the same plane as the circuit board-mounting face and workingas an external electrode terminal.

According to a sixth aspect of the present invention, there is provideda semiconductor element-mounting board according to any one of the firstthrough fourth aspects, wherein the conductive member has a projectingpart projecting from the circuit board-mounting face.

According to a seventh aspect of the present invention, there isprovided a semiconductor element-mounting board according to the sixthaspect, wherein the project part is tapered.

According to an eighth aspect of the present invention, there isprovided a method for manufacturing a semiconductor element-mountingboard. The semiconductor element-mounting board comprises a base memberwhich includes a semiconductor element-mounting face to which asemiconductor element is mounted and electrically connected by aflip-chip mounting method. The base member also includes a circuitboard-mounting face opposite to the semiconductor element-mounting faceand mounted to a circuit board. The base member is formed of anelectrically insulating resin material in one layer. The semiconductorelement-mounting board also comprises linear conductive members whichare nearly (substantially) orthogonal to the semiconductorelement-mounting face and the circuit board-mounting face. The linearconductive members extend linearly to penetrate to an interior of thebase member thereby to electrically connect the semiconductor elementwith the circuit board.

The method of manufacturing the semiconductor element-mounting boarddescribed above includes initially arranging the conductive members in amold. Then, the resin material for forming the base member is injectedinto the mold so that the conductive members and the resin material areintegrally molded.

According to a ninth aspect of the present invention, there is provideda manufacturing method according to the eighth aspect, furthercomprising, after the injecting of the resin, forming a wiring to beelectrically connected with the conductive members. The wiring is formedon the semiconductor element-mounting face and the circuitboard-mounting face of the base member.

According to a 10th aspect of the present invention, there is provided amanufacturing method according to the ninth aspect, further comprisingmachining an outer face of the base member after the injecting of theresin and before the wiring-forming.

According to an 11th aspect of the present invention, there is provideda manufacturing method according to any one of the eight through 10thaspects, further comprising, after the injecting of the resin, cutting abase member block molded by injecting the resin material into the moldwith the conductive member arranged therein. The base member mold is cutin a direction orthogonal to axial directions of the conductive membersto thereby obtain the base members.

According to a 12th aspect of the present invention, there is provided amanufacturing method according to any one of the eight through 11thaspects, further comprising turning rough contact faces between theconductive members and the resin material to increase adhering forcestherebetween before the conductive members are set in the mold for theinjecting.

According to a 13th aspect of the present invention, there is provided amanufacturing method according to the 12th aspect, further comprisingapplying an adhesion-increasing agent to the contact faces instead ofturning the faces rough.

According to a 14th aspect of the present invention, there is provided amanufacturing method according to any one of the eight through 13thaspects, wherein during the injecting, the resin material is injected toflow in the axial directions of the conductive members through at leasttwo injection openings arranged symmetric to each other with respect toeach of the conductive members.

According to a 15th aspect of the present invention, there is provided amanufacturing method according to the 14th aspect, wherein the mold hasa first holding plate holding axial first ends of the conductive membersand having the injection openings extending in the axial directions ofthe conductive members. A second holding plate holds the other ends ofthe conductive members and is movable in the axial direction. A pressureregulation mechanism is provided that allows the second holding plate tomove in the axial direction in response to the compression/extension ofthe conductive members due to the injected resin material.

During the injecting in this 15th aspect, the second holding plate ismoved in the axial direction in response to the compression/extension ofthe conductive members due to the injected resin material, therebyrestricting bends in the conductive members.

According to a 16th aspect of the present invention, there is provided amanufacturing method according to any one of the eighth through 13thaspects, wherein during the injecting, the resin material flows in theaxial directions of the conductive members after being injected into avicinity of the axial first ends of the conductive members through aplurality of injection openings formed in the vicinity of the axial oneends of the conductive members supported by the mold.

According to a 17th aspect of the present invention, there is provided amethod for manufacturing a semiconductor element-mounting board, thesemiconductor element-mounting board comprises a semiconductor elementmounted and electrically connected by a flip-chip mounting method. Thebase member also includes a circuit board-mounting face opposite to thesemiconductor element-mounting face and mounted to a circuit board. Thebase member is formed of an electrically insulating resin material inone layer. The semiconductor element-mounting board also compriseslinear conductive members which are nearly orthogonal to thesemiconductor element-mounting face and the circuit board-mounting face.The linear conductive members extend linearly to penetrate an interiorof the base member thereby to electrically connect the semiconductorelement with the circuit board.

The method of manufacturing the semiconductor element-mounting boarddescribed above includes injecting the resin material into a mold sothat through holes are formed to penetrate the semiconductorelement-mounting face and the circuit board-mounting face to mold thebase member. The method also comprises inserting the conductive membersin the through holes.

According to an 18th aspect of the present invention, there is provideda manufacturing method according to the 17th aspect, further comprising,after the conductive members are inserted into the through holes,forming a wiring to the semiconductor element-mounting face, the circuitboard-mounting face of the base member, and an inner wall face of one ofthe through holes.

According to a 19th aspect of the present invention, there is provided amanufacturing method according to the 17th or 18th aspect, furthercomprising, after the injecting, cutting a molded base member blockprovided with the through holes. The base member mold is cut in adirection orthogonal to an extending direction of the through holes toform the base member.

According to a 20th aspect of the present invention, there is provided amanufacturing method according to the eighth or 17th aspect. This methodfurther comprises, after the injecting, forming at the conductive membera projecting part projecting from the circuit board-mounting face. Themethod of the 20th aspect of the present invention also comprisesperforming plastic treatment on the projecting part so as to form a landto be connected to the circuit board.

According to a 21st aspect of the present invention, there is provided amanufacturing method according to the 20th aspect, wherein in formingthe projecting part, the method comprises leveling the base member withthe conductive member so that a thickness of the base member is equal toa length of the conductive member. Thereafter, only the base member isremoved in a thicknesswise direction.

According to a 22nd aspect of the present invention, there is provided amanufacturing method according to the 21st aspect, wherein the removingof the base member is conducted by any of wet etching, dry etching,sandblasting, and machining.

According to a 23rd aspect of the present invention, there is provided amanufacturing method according to the ninth or 18th aspect, wherein thewiring is obtained by forming the wiring by etching after plating aconductor on the base member, or by plating only a necessary part to bewired.

According to a 24th aspect of the present invention, there is provided amanufacturing method according to the ninth or 18th aspect, wherein thewiring is obtained by printing and heating a conductive paste on thebase member.

According to a 25th aspect of the present invention, there is provided asemiconductor device which has a semiconductor element mounted on,electrically connected to, and sealed to the semiconductorelement-mounting face of the semiconductor element-mounting boardaccording to the first aspect.

According to a 26th aspect of the present invention, there is provided asemiconductor device according to the 25th aspect, wherein thesemiconductor element is sealed by forming an end face of a sealantalong a side face of the semiconductor element-mounting board which isnearly parallel to a thicknesswise direction of the semiconductorelement-mounting board.

According to a 27th aspect of the present invention, there is provided amethod for manufacturing a semiconductor device. This method comprisesmounting and electrically connecting a plurality of semiconductorelements to the semiconductor element-mounting face, of thesemiconductor element-mounting board according to the first aspect. Theplurality of mounted semiconductor elements is simultaneously sealed bysealing resin. Finally, the semiconductor element-mounting board and thesealing resin is cut between the semiconductor elements.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and features of the present invention willbecome clear from the following description taken in conjunction withthe preferred embodiments thereof with reference to the accompanyingdrawings, in which:

FIG. 1 is a sectional view showing the structure of a semiconductorelement-mounting board in an embodiment of the present invention;

FIG. 2 is a sectional view of an example of the constitution atelectrically connected parts between conductive members of thesemiconductor element-mounting board and a circuit board of FIG. 1;

FIG. 3 is a sectional view of a different example of the constitution atelectrically connected parts between conductive members of thesemiconductor element-mounting board and a circuit board of FIG. 1;

FIG. 4 is a sectional view of a further different example of theconstitution at electrically connected parts between conductive membersof the semiconductor element-mounting board and a circuit board of FIG.1;

FIG. 5 is a sectional view showing the structure of a semiconductorelement-mounting board in a different embodiment of the presentinvention;

FIGS. 6A, 6B, and 6C are diagrams showing steps of a method for formingbonding lands in the semiconductor element-mounting board of FIG. 5;

FIG. 7 is a flow chart of an example of a manufacturing method for thesemiconductor element-mounting board of FIG. 1;

FIG. 8 is a flow chart of another example of the manufacturing methodfor the semiconductor element-mounting board of FIG. 1;

FIG. 9 is a perspective view of the semiconductor element-mountingboard, explaining an example of the manufacturing method for thesemiconductor element-mounting board of FIG. 1;

FIG. 10 is a perspective view of the semiconductor element-mountingboard, showing a different example of the manufacturing method for thesemiconductor element-mounting board of FIG. 1;

FIG. 11 is a sectional view when an adhesion-increasing agent isprovided between the conductive members and the base member of thesemiconductor element-mounting board of FIG. 1;

FIG. 12 is a sectional view of the semiconductor element-mounting boardhaving a conductive film formed to provide the semiconductorelement-mounting board of FIGS. 1 and 5 with a wiring;

FIG. 13 is a diagram showing how the semiconductor element-mountingboard of FIGS. 1 and 5 is provided with the wiring;

FIG. 14 is a plan view of a first holding plate of a mold used inmanufacturing the semiconductor element-mounting board of FIG. 1;

FIG. 15 is a diagram showing how a resin material flows in the mold usedin manufacturing the semiconductor element-mounting board of FIG. 1;

FIG. 16 is a diagram of a second holding plate and a pressure regulationmechanism of the mold used in manufacturing the semiconductorelement-mounting board of FIG. 1;

FIG. 17 is a sectional view of a different mold used in manufacturingthe semiconductor element-mounting board of FIG. 1;

FIG. 18 is a sectional view showing the structure of a semiconductordevice according to an embodiment of the present invention;

FIG. 19 is a sectional view of a different semiconductor device fromFIG. 18;

FIG. 20 is a flow chart of a method for manufacturing the semiconductordevice of each of FIGS. 18 and 19;

FIG. 21 is a sectional view of the structure of a conventionalsemiconductor device;

FIG. 22 is a flow chart of a conventional manufacturing method for thesemiconductor device; and

FIG. 23 is a flow chart of a conventional method for manufacturing asemiconductor element-mounting board.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Before the description of the present invention proceeds, it is to benoted that like parts are designated by like reference numeralsthroughout the accompanying drawings.

A semiconductor element-mounting board, a manufacturing method for thesemiconductor element-mounting board, a semiconductor device using thesemiconductor element-mounting board, and a manufacturing method for thesemiconductor device of an embodiment of the present invention will bedescribed with reference to the drawings in which the same parts orfunctionally equal parts are designated by the same reference numerals.

First, the semiconductor element-mounting board will be described.

A semiconductor element-mounting board 101 shown in FIG. 1 is generallycalled a carrier and corresponds to the semiconductor element-mountingboard 2 described with reference to FIG. 21. Roughly speaking, the board101 comprises a base member 100 including resin material 102 and linearconductive members 103. In the board 101, a semiconductor element is tobe mounted and electrically connected at a semiconductorelement-mounting face 104 by a flip-chip mounting method, and a circuitboard is to be mounted and electrically connected at a circuit boardmounting face 105 of the base member 100 opposite to the mounting face104.

Each of the linear conductive members 103 is nearly orthogonal to themounting faces 104 and 105 of the base member 100. At the same time,each of the linear conductive members 103 extends linearly to penetratethe resin material 102 of base member 100. The conductive members 103are formed so as to not touch each other in the base member 100. Eachlayer conductive member 103 is an interlayer conduction part fortransmitting electric signals between the mounting faces 104 and 105,corresponding to the conventional via hole or through hole A metallicwire of a material selected from Cu, Au, Al, Ag, Pd and Pt or an alloywire including at least one of the above metals can be used for theconductive member 103. Particularly a conductive member 103 of Au ispreferred because of availability, stable quality without oxidation orthe like quality change and a low resistance for use in narrow-pitch andmulti-pin ICS.

Each conductive member 103 is formed of the metallic wire of, e.g.,0.1–0.15 mm diameter and arranged with, e.g., 0.3 mm pitch along, forinstance, peripheral edge parts of the mounting faces 104 and 105 of thebase member 100.

In one embodiment, the base member 100 is formed of a resin material 102in one layer. The resin material should have such specific properties asgood fluidity, 250° C. or higher heat resistance and 15 ppm or lowerthermal expansion coefficient, while also allowing plating on to themounting faces 104 and 105. Although any of thermosetting andthermoplastic resins can be used as the resin material, thethermosetting resin is preferable for its low viscosity from theviewpoint of adhesion to the conductive member 103 and injectionconvenience between the linear conductive members 103. However, athermoplastic resin such as liquid crystal polymer, etc. may be used aswell.

Although described later in detail, the semiconductor element-mountingboard 101 in the above structure is obtained by locating the linearconductive members 103 in molds, and injecting the resin material whichforms the base member 100 into the molds. In contrast to theconventional semiconductor element-mounting board 2, the base member 100with the conductive members 103 can be formed in one piece in thepresent semiconductor element-mounting board 101. Therefore, the board101 can be obtained in a simplified process at low cost. A manufacturelead time is shortened and productivity is improved. The semiconductorelement-mounting board 101 does not create a filling failure which isgenerated when the conductive paste is filled in the interlayerconduction part 5 in the prior art. It also does not create amalfunction even after experiencing 1000 times or more thermal shocktests at −55° C. to 125° C. The semiconductor element-mounting board 101shows improved reliability to disconnection, etc. Furthermore, each ofthe linear conductive members 103 of the mounting board 101 extendslinearly through the resin 102 of base member 100 between the mountingfaces 104 and 105. Therefore, conduction resistance is decreased so asto be no larger than 1 mΩ if a metallic wire of a low intrinsic volumeresistivity is used for the conductive member 103. The use of themetallic wire for the conductive member 103 helps to preventdisconnections and can improve reliability and resistance to breakdown.

An arrangement interval of the linear conductive members 103 can bereduced in the mounting board 101 of this embodiment as compared withthat of the interlayer conduction parts 5 of the conventional mountingboard 2. The reason for this will be discussed below.

The lands 18 are formed at the mounting face 2 b of the conventionalmounting board 2, as indicated by dotted lines in FIG. 2. Each land 18is required to be larger in diameter than the interlayer conduction part5 formed in the conventional board 2. In other words, the interval ofthe interlayer conduction parts 5 is dependent on the diameter of eachland 18 and therefore is set larger than required. Meanwhile, the linearconductive members 103 of the metallic wire are arranged beforehand informing the mounting board 101 of the present invention. Thus, theunavoidable necessity in the prior art of boring the base member andburying the conductive members in the bored holes is eliminated. At thesame time, in the mounting board 101 of the embodiment, the wiring isattained by etching of the mounting face 105 which will be describedlater, so that the necessity for forming lands at the mounting faces 105is eliminated. The interval of the linear conductive members 103 isaccordingly not dependent on the diameter of the land. Consequently, theinterval of the linear conductive members 103 can be reduced, and themounting board 101 becomes fit to narrow-pitch, multi-pin ICS.

As shown in FIG. 3, each linear conductive member 103 may be projectedbeyond the mounting face 105 of the mounting board 101 of thisembodiment towards a circuit board 201 so as to constitute a projectingpart 106. The projecting part 106 functions as an external electrodeterminal. Due to the projecting part 106, a bonding material 220, whichis generally solder used for electrically connecting the conductivemember 103 with a land 202 on the circuit board 201, wets and spreads onthe projecting part 106 and is sucked to the side of the board 101 viathe projecting part 106. The provision of the projecting parts 106allows the bonding material 220 in a melting state to generate ameniscus between the projecting part 106 and a respective land 202 onthe circuit board 201. Therefore, even when the conductive members 103are arranged, for instance, every 0.3 mm distance in the board 202, afailure such as a bridge or the like is prevented from being generatedbetween the adjacent lands 202 of the circuit board 201. Accordingly,the mounting boards 101 is applicable to multi-pin semiconductorelements.

The above projecting part 106 may be tapered to, for example, a conicalshape towards the circuit board 201, as in FIG. 4. The conical shapereduces a contact area between the projecting part 106 and land 202. Asa result, the friction force between the projecting part 106 and land202 is reduced, whereby a surface tension is applied from the moltensolder 220 to the projecting part 106, enabling the projecting part 106to easily slide on the land 202. A front end part 106 a of theprojecting part 106 is therefore positioned at a central part of theland 202 due to a self alignment effect. A positional shift of themounting board with respect to the lands 202 spaced every 0.5 mm can beprevented even when the semiconductor element is mounted to the circuitboard 201 with a mounting positional accuracy of ±0.1 mm.

The above projecting part 106 may be formed in a semicircular sectionalshape as indicated in FIG. 5 to work as a bonding land 120 to beelectrically connected to the wiring on the circuit board 201. Thebonding land 120 is obtained as shown in the sequence of steps of FIGS.6A–6C.

The projecting parts 106 are formed first as described above. In FIG.6B, the projecting parts 106 are arranged in a mold 121 designed toshape the projecting parts 106 in a required form. That is, an uppermold unit of the mold 121 has a flat surface capable of coming intocontact with the surface opposite to the mounting face 105, and a lowermold unit of the mold 121 has hemispherical (concave) recesses on itssurface. A pressure is applied from above and below by the mold 121,thereby changing the projecting parts 106 into the shapes of therecesses in the lower mold unit of the mold. Thus, the bonding lands 120are molded.

The bonding land 120 is larger in diameter than the linear conductivemember 103. Thus, the conductive member 103 is prevented from beingseparated from the mounting board 101 because of shocks, etc.Experiments show that the shape of the solder used when the mountingboard 101 is mounted to the circuit board 201 is changed depending onthe shape of the bonding land 120 formed at the mounting board 101. Asufficient bonding strength can be secured between the mounting board101 and the circuit board 201 if the bonding land 120 is processed intothe required shape. Since many bonding lands 120 of the required shapeare obtained at one time in the process, the manufacture lead time canbe shortened. The semispherical front end of the conductive member 103changes moderately to the mounting face 105 so that the concentration ofstress resulting from a thermal expansion difference or the like iseliminated. Thus, reliability is enhanced.

The projecting parts 106 may be formed by projecting the conductivemembers 103 to the side of the circuit board 201 over the mounting face105 in the above-described example. Alternatively, the projecting parts106 can be obtained by removing the base member 102 at the side of themounting face 105 thereby to project the conductive members 103, whichwill be depicted below.

Specifically, as shown in FIG. 2, the mounting board 101 is molded sothat the circuit board mounting face 105 of the base member is even withthe end faces of the linear conductive members 103. Thereafter, the basemember 102 is removed to be a predetermined thickness, e.g., by dryetching sandblasting, buffing or with the use of a strong alkalisolution, etc. The removing method is different for the resin material102 used in the base member 100. For instance, when an epoxy resin isused in the base member 100, reacting ion etching (RIE) is selected.Only the resin material 102 is dry-etched using Cl₂ as an atmosphericgas by 50 scm at 30 mTorr and 300 W output.

Since it is possible to remove the resin material 102 alone in the abovemethod, the projecting parts 106 can be formed in the mounting board 101after the base member 100 is formed and cut to be a predetermined size.Even if the mounting board 101 does not have a required bonding strengthas it is, the required strength can be obtained by the process ofshaping the bonding lands as described above in the mounting board 101.

A manufacturing method for the above semiconductor element-mountingboard 101 will now be described.

In step 101 in FIG. 7, the linear conductive members 103 are arranged inthe mold to form a conduction part between the mounting faces 104 and105. This process corresponds to step 14 of FIG. 23 related to themanufacture of the conventional semiconductor element-mounting board 2,i.e., forming of holes by punching a ceramic green tape.

In this embodiment, 65 grid-like conductive members 103 are formed atone time. In step 102, the resin material 102 is injected into the moldso as to form the base member 100. At this time, the resin material isalso filled in between the conductive members 103. After thesemiconductor element-mounting board 101 is molded in this manner, thewiring is formed on the mounting faces 104 and 105 of the base member100 101 in step 103.

As is clear in comparison between FIGS. 7 and 23, the manufacturingprocess of the mounting board 101 in the embodiment can be considerablysimplified, whereby the mounting board 101 can be manufactured at lowcosts.

A step 104 is preferably added between the steps 102 and 103, asindicated in FIG. 8, to machine the molded semiconductorelement-mounting board. The machining in step 104 is, for example,cutting of the mounting board to a predetermined size. Morespecifically, a base member block 107 represented by chain double-dashedlines in FIG. 9 and formed through steps 101 and 102 is cut along acutting line 108. Therefore, the shape of the mounting board 101 can bedetermined without any limitation to the type of mold used. According tothis embodiment, after the base member block 107 is formed by the 17×12mm mold, the block is machined to 15×6 mm rectangles in step 104, towhich the wiring is provided on the mounting faces 104 and 105 in step103.

Alternatively, as shown in FIG. 10, when the base member block 107 isformed, the base member block 107 can be cut to layers along cuttinglines 108. In this case, conductive members 103 are exposed on themounting faces 104 and 105 of the cut mounting board 101. Cutting by awire or a metal slitting saw, etc. is considered for the above cuttingmethod, but grinding is preferable in terms of accuracy at cutting facesand productivity. In this embodiment, the base member block 107 is cutby rotating a blade with abrasive grains of artificial diamond at 8000rpm. After the base member block 107 is cut to a predeterminedthickness, the wiring is formed at necessary part of the mounting faces104 and 105 of the mounting board 101 as mentioned before. Although aplurality of semiconductor element-mounting boards 101 are cut out fromthe base member block 107 in the above description and FIG. 10, onesheet of the mounting board 101 may also be obtained from the basemember block 107.

As described hereinabove, a plurality of semiconductor element-mountingboards 101 can be continuously manufactured from one base member block107 simply by the addition of the cutting process to the base memberblock 107 which is produced in a simplified manner as compared with theprior art. Therefore, the manufacturing method of this embodimentshortens the manufacture lead time and minimizes costs.

Now, the semiconductor element-mounting board 101 having improved tightcontact and adhesive properties of the linear conductive members 103 tothe resin material constituting the base member 102 will be describedbelow.

In many cases, circuits formed on a circuit-forming face of thesemiconductor element are of silicon or aluminum vapor-deposited film,and are considerably weak to water and ions, etc. Therefore, thesemiconductor element is generally sealed when mounted. In this case, ifthe linear conductive members 103 are poorly adhesive to the resinmaterial 102 in the mounting board 101, water invades through aninterface between them and the board fails in a reliability test,specifically, the pressure cooker test (PCT). A bonding layer becomesconsequently necessary to keep the conductive members 103 fully in tightcontact with the resin material.

In this embodiment, an adhesion-increasing agent 109 is applied tosurface 103 a of the conductive members 103 which contacts the resinmaterial, as shown in FIG. 11. The presence of the adhesion-increasingagent 109 improves the contacting and adhering properties of the contactsurfaces 103 and base member 100, so that the invasion of water and ionsto the contact faces 103 a can be prevented. The adhesion-increasingagent 109 used is the semiconductor sealant resin in this embodiment.

After the adhesion-increasing agent 109 is applied to the linearconductive members 103, the semiconductor element-mounting board 101 issubjected to a reliability test, the results of which is shown in Table1.

TABLE 1 PCT: 121°, 2 atm, 300 hours later Board Without Agent Board WithAgent Disconnected 25 hours later Disconnection not generated

As is clear from Table 1, a disconnection is not caused because theadhesion-increasing agent 109 is applied to the linear conductivemembers 103. The reliability of the mounting board 101 is thus improved.

The adhesion-increasing agent 109 is not limited to the above-mentionedsemiconductor sealant resin, and any material can be used so long as itimproves the adhesive and tight contact, properties between theconductive member 103 and the resin material 102.

In order to improve the contacting and adhesive properties between theconductive members 103 and resin material 102, the contact faces of thelinear conductive members 103 to the resin material 102 may be processedto be rough, instead of applying the adhesion-increasing agent 109.

Next, the step 103, how to form the wiring in the mounting board 101will be detailed.

FIG. 12 is a sectional diagram of the semiconductor element-mountingface 104 of the mounting board 101. As shown in FIG. 12, a conductivefilm 122 is formed on the mounting face 104. The resin material 102 forthe base member 100 of the mounting board 101 is LCP Sumika Super E6510Pproduced by Sumitomo Chemical Company, Limited, and the conductive film122 is plated to the mounting face 104 through an acid/alkali process.As a result of the plating, minute recesses 123 are formed in themounting face 104 of the base member 100 of the mounting board 101 asshown in FIG. 12. The adhesion can be secured between the conductivefilm 122 and base member 100 due to an anchor effect of conductorsdeposited in the recesses 123. Moreover, a metallic bond is generated atan interface 124 between the conductive film 122 and each linearconductive member 103, thus bonding the conductive film 122 and linearconductive member 103 strongly.

The wiring may be formed by etching this conductive film 122.Alternatively, the conductive film 122 is plated only to a part to bewired.

In an example of FIG. 13, the wiring is obtained by printing of aconductive paste. Reference numerals in FIG. 13 are: 125 a mask; 126 asqueegee; and 127 a conductive paste. The conductive paste 127 in thisembodiment is obtained by dispersing copper particles in an epoxy resin.The resin material of the conductive paste 127 is LCP XYDAR G330produced by Nihon Sekiyu Kagaku Kabushiki Kaisha After the wiring isformed on the mounting faces 104 and 105 by printing as shown in FIG.13, the resin material of the conductive paste 127 is heated and set,thereby completing the wiring process. Although a proper viscosity ofthe resin material of the conductive paste 127 differs depending on awiring pitch, if the viscosity is adjusted to be a required value,defects such as oozing or short circuits, etc. can be avoided. Thewiring obtained in this method is free from defects. Even resinmaterials of non-plating grade can, display an adhesion strength in thewiring. While the conductive paste 127 used in the embodiment has copperparticles dispersed in the epoxy resin, a sintered paste usingindividual dispersion superfine particles produced by Shinku YakinKabushiki Kaisha may also be used, in which case the same effects can beachieved.

According to the above wiring method using the conductive paste 127, itis possible to form conductors in the base member 100 even if theconductive film 122 unable to be plated. Therefore, any resin materialwith required characteristics is selectable for the base member 100irrespective of whether or not the conductive film 122 can be plated tothe resin material. The method enables a wide variety of semiconductorelements to be mounted onto the mounting board.

The mold for molding the above semiconductor element-mounting board 101will be described next.

FIG. 14 is a plan view of a first holding plate 110 constituting onewall face of the mold and holding a first axial end of each linearconductive member 103. In FIG. 14, the linear conductive members 103extend in a direction orthogonal to the drawing sheet. A plurality ofinjection openings 111 are formed penetrating through the first holdingplate 110 in the orthogonal direction so as to inject a fluid resinmaterial 112 into the mold and sets to form the hardened resin 102 ofthe base member 100. The injection openings 111 are arranged, as isobvious from FIG. 14, symmetrically to each other with respect to eachconductive member 103.

Since the injection openings 111 are formed at the above position withrespect to the linear conductive member 103, when the fluid resinmaterial 112 flows along the side face of the linear conductive member103, the linear conductive member 103 is less influenced by a forceapplied from the fluid resin material 112 in a direction orthogonal tothe axial direction. Therefore, the linear conductive members 103 can beenclosed within the base member 100 while maintaining their positionalaccuracy in the arrangement. In comparison with the case where the fluidresin material 112 is injected into the mold through a single injectionopening, a positional shift of the linear conductive member 103 can belimited to 10% or lower. Accordingly, the mounting board 101 can beimproved in yield.

FIG. 15 shows the behavior of the fluid resin material 112 flowing inthe axial direction in the periphery of the linear conductive members103. The fluid resin material 112 runs in a direction indicated byarrows 113. The fluid resin material 112 becomes wide in diameter afterentering the mold through the injection openings 111, inducing thelinear conductive members 103 to be positionally shifted by forces whichdepend on the viscosity and entering speed of the fluid resin material112. However, as is clearly shown in FIG. 15, a hydrostatic pressure isimpressed uniformly to each of the conductive members 103 from theperiphery because the conductive member is free from an extension stressdue to a fountain-like flow of the fluid resin material 112.Accordingly, the linear conductive member 103 can be prevented frombeing positionally shifted even when the fluid resin material 112 entersthe mold.

FIG. 16 illustrates a mechanism for more efficiently restricting thepositional shift of the conductive member 103 subsequent to theinjection of the fluid resin material 112.

Referring to FIG. 16, the other ends of the linear conductive members103 are held by a second holding plate 114 which constitutes one wallface of the mold and is movable in the axial directions of theconductive members 103. A pressure regulation mechanism 115 is linked tothe second holding plate 114, which acts as follows. The pressureregulation on mechanism 115 imparts a tensile force to the conductivemembers 103, both ends of each of which are held by the first and secondholding plates 110, 114. The tensile force prevents each of the linearconductive members 103 from being bent or positionally shifted when thefluid resin material 112 is injected in the mold. More specifically, thepressure regulation mechanism 115 moves the second holding plate 114 inthe axial direction of the conductive members 103 in difference betweenan injection pressure of the regulation mechanism 115. An elastic membersuch as a spring, a leaf spring, etc. can be used for the pressureregulation mechanism 115, or a compressible fluid. Air is preferablefrom the economic viewpoint in addition to its easy-to-regulateconvenience.

In the presence of the pressure regulation mechanism 115 as describedabove, when the fluid resin material 112 flowing into the mold from theinjection openings 111 applies pressure to the second holding plate 114,the second holding plate 114 is thereby moved to add the tension to thelinear conductive members 103. The linear conductive members 103 can bebent less due to this tension. Since the second holding plate 114 ismovable, the tension acting on the linear conductive members 103 whenthe fluid resin material 112 enters the mold can be adjusted, making itpossible to increase the injection pressure of the fluid resin material112.

If a pressuring mechanism for the linear conductive members 103 isfitted to the second holding plate 114, when the conductive members 103are sequentially sent into the mold and the pressure regulationmechanism 115 is moved stepwise in the right direction of the drawing,the linear conductive members can be sequentially molded to respectivepredetermined lengths. That is, the linear conductive members can becontinuously molded as in hoop molding.

The structure of another mold will be depicted with reference to FIG.17.

In comparison with the mold described with reference to FIGS. 14 and 16,the mold of FIG. 17 has injection openings for the fluid resin material112 at a different position. That is, in the mold in FIG. 17, theinjection openings 118 are formed in the vicinity of a third holdingplate 116 holding the linear conductive members 103. The injectionopenings 118 are inclined an angle allowing the fluid resin material 112to flow towards holding parts between the linear conductive members 103and third holding plate 116 to a central part of the third holding plate116. Seen from a plane of the third holding plate 116, at least twoinjection openings 118 are arranged opposite to each other. Theaforementioned angle, location and opening diameter of the injectionopenings 118 act to reduce the force impressed upon the linearconductive members 103, and the angle depends on a melt viscosity and asolidification speed of the fluid resin material 112.

Due to the injection openings 118 arranged as above, the fluid resinmaterial 112 flows in ways indicated by arrows 119 in FIG. 17 intospaces 117 in the mold. The linear conductive members 103 can beprevented from being positionally shifted by the fluid resin material112 injected from the direction almost orthogonal to the axialdirections of the conductive members 103. This will be proved, forexample, from the amount of a bend of a cantilever.

A deflection amount y at a position x from a fixed end of the cantileveris expressed as follows, supposing that a uniform distributed load p isapplied to the cantilever:y=px ⁴/8EI.In this equation, E is Young's modulus and I is a second moment ofinertia of the linear conductive member 103. The uniform distributedload p is applied in the form of a drag D to a fluid. D is represented:D=C _(D) ρV ² S/2.In this equation C_(D) is a drag coefficient of an object and adimensionless number depending on a shape of the object, ρ is a densityof the fluid, V is a velocity of the fluid, and S is a projected area ofthe conductive member 103 to a face vertical to the flow of the fluid.

The above fluid is namely the fluid resin material 112 and therefore isestimated to have a density of 1. The deflection amount y of theconductive member 103 is accordingly obtained by:y=C _(D) ρV ² Sx ⁴/16EI.The deflection amount of the conductive member 103 can be reduced bydirecting the fluid, i.e., fluid resin material 112, to the holding partof the conductive member 103 in the vicinity of the third holding plate116 as much as possible.

The same effect can be accomplished also by reducing a length of theconductive member 103 in the space 117 filled with the fluid resinmaterial 112. Although the foregoing description is related to thecantilever, the same principle is true for a beam with both ends fixed,because the denominator 8 simply changes to 384.

Each amount of the positional shifts of the conductive members when theinjection openings 118 are provided as in FIG. 17 and when one injectionopening is formed is indicated in Table 2.

TABLE 2 One injection opening Embodiment 400 μm 50 μm

As is clear from Table 2, the shifting amount is favorably decreased inFIG. 17.

The linear conductive members 103 are installed beforehand according tothe manufacturing method for the semiconductor element-mounting board101 which is described referring to FIGS. 7 and 8, in the mold forforming the base member 100 of the mounting board 101 which is describedwith reference to FIGS. 14–17. As will be described herein below, themounting board can be manufactured by inserting the conductive members103 after forming insertion holes for the conductive members 103.

Specifically, columns of a predetermined size are erected in the moldhaving a space of the required size, or the mold provided with columnsof a predetermined size is prepared. Then, the fluid resin material 112is injected into the spaces in conformity with conditions required forthe mounting board. Only the set resin material 102 is taken out fromthe mold thereafter. The base member with holes is obtained in thismanner. Subsequently, conductive members of the same size as the holesare inserted into the holes of the base member or the conductive pasteis filled in the holes. The conductive members or conductive pastebecomes a path, transmitting electric signals from the semiconductorelement-mounting face to the circuit board-mounting face of the mountingboard.

Moreover, since the columns for forming the holes are fixed to the mold,the positional shifts brought about in the conventional punching methodare eliminated, so that the conduction parts can be defined accurately.

The whole surface of the base member, including inner walls of theholes, are once plated to form conductors. Conductors of an unnecessarypart are removed by etching or the like manner, whereby the wiring isobtained.

Plating facilities conventionally used for manufacturing of printedcircuit boards is used in the above method, thus requiring no investmentin facilities.

Using the mounting board 101, a semiconductor device 130 obtained bymounting/electrically connecting a semiconductor element to the mountingface 104 of the mounting board 101 described above will be depicted withreference to FIGS. 18–20.

In step 111 of FIG. 20, projecting electrodes 134 are formed onelectrode parts 133 at a circuit formation face 132 (i.e., active side)of a semiconductor element 131. Each projecting electrode 134 is madelevel in step 112, and a conductive paste 135 is transferred to theprojecting electrode 134 in step 113. After the transfer of theconductive paste 135, the circuit formation face 132 of thesemiconductor element 131 is brought to face the mounting face 104 ofthe mounting board 101 in step 114.

In the meantime, as shown in FIG. 18, the mounting face 104 of themounting board 101 is provided with a wiring 128 and lands 129 asdescribed before.

In step 115, the land 129 of the mounting board 101 is electricallyconnected via the conductive paste 135 to the projecting electrode 134of the semiconductor element 131. In step 116, the conductive paste 135is hardened. The semiconductor element 131 is mounted to the mountingface 104 of the mounting board 101. The semiconductor element 131 issealed at the mounting face 104 by a sealant 436 in step 117. Thesealant 436 is set in step 118. If a plurality of semiconductor elements131 are mounted on the mounting board 101, in step 119, thesemiconductor elements 131 are cut and separated from each other in athicknesswise direction of the mounting board 101. The semiconductordevice 130 is completed in this manner. The semiconductor device 130 ismounted to the circuit board 201 as indicated in the drawing byconnecting a land 136 on the mounting face 105 of the mounting board 101with the land 202 of the circuit board 201 via the conductive bondingmaterial 220.

The thus-constituted semiconductor device 130 uses the mounting board101 manufactured inexpensively with the short lead time as describedbefore. Therefore, the semiconductor device can be obtained at lowmanufacturing costs with a short lead time.

Mismatching of thermal expansion coefficients of the semiconductorelement 131 and circuit board 201 is absorbed by the mounting board 101.Therefore, the semiconductor device has improved bonding reliability tothe circuit board as compared with when the semiconductor element isdirectly mounted to the circuit board.

Although it is difficult to judge a known good die (KGD) if thesemiconductor element of a single body is to be judged, the judgement iseasily executed by enlarging an electrode pitch of the semiconductorelements via the mounting board 101. In addition, since the mountingboard 101 can be manufactured at low cost, losses due to defectivesemiconductor elements 131 can be limited in the semiconductor device.The mounting board 101 may be used as a socket for the KGD.

According to the present embodiment, the semiconductor element 131 iselectrically connected to the mounting board 101 via the projectingelectrodes 134 and conductive paste 135. However, the semiconductorelement 131 may be electrically connected with the mounting board 101via a metallic bonding of Au and Au or Au and Sn.

As shown in FIG. 19, the sealant 436 is preferably injected so that anend face 436 a of the sealant 436 is formed along an extension line of aside face 137 of the mounting board 101. When the sealant 436 isinjected in this manner, an upper face 436 b of the sealant 436 does notneed to be even with an upper face 131 a of the semiconductor element131 as indicated by chain double-dashed lines 138, although both faces436 b and 131 a are even in FIG. 19.

Since the sealant 436 for protecting the circuit formation face 132 ofthe semiconductor element 131 is increased in thickness in asemiconductor device 140 of FIG. 19 in comparison within theconventional structure, the semiconductor device 140 is more resistantto the invasion of water. Accordingly, even a device conventionallydetermined to be defective in the reliability test can be improved inreliability with regard to water to pass the reliability test. The priorart and the embodiment are compared in the PCT, the result of which isshown in Table 3.

TABLE 3 PCT: 121° C., 2 atm Prior art Embodiment 100 hours 500 hours

As is fully described above, according to the semiconductorelement-mounting board in the first aspect of the present invention andthe manufacturing method for the semiconductor element-mounting board inthe eight and 17th aspects of the present invention, the base member isconstituted by a single layer of the resin material and the conductivemembers which extend linearly to penetrate the base member of the resinmaterial. The structure is accomplished simply by injecting the resinmaterial into the mold where the conductive members are arrangedbeforehand. Therefore, the process can be simplified as opposed to theprior art, and can be reduced in cost and lead time so that theproductivity can be improved.

Since the conductive members extend linearly in the base member, theconduction resistance can be lower than in the prior art, and themounting reliability to the circuit board can be improved.

Since the conductive members are set in the base member beforehand, aconventionally required land on the circuit board-mounting face can beeliminated, enabling the arrangement pitch of conductive members to benarrow in comparison with the prior art, which is suitable to multi-pinICS.

According to the semiconductor device in the 25th aspect of the presentinvention and the manufacturing method for the semiconductor device inthe 27th aspect of the present invention, the above-describedsemiconductor element-mounting board is used, whereby the manufacturingprocess can be simplified and reduced in cost and lead time, withproductivity improved. The present invention can be used with multi-pinICS and improve mounting reliability onto the circuit board.

The entire disclosure of Japanese Patent Application No. 8-179031 filedon Jul. 9, 1996, including specification, claims, drawings, and summaryare incorporated herein by reference in its entirety.

Although the present invention has been fully described in connectionwith the preferred embodiments thereof with reference to theaccompanying drawings, it is to be noted that various changes andmodifications are apparent to those skills in the art. Such changes andmodifications are to be understood as included within the scope of thepresent invention as defined by the appended claims unless they departtherefrom.

1. A method of manufacturing a semiconductor element-mounting board,comprising: arranging a plurality of conductive members in a mold;injecting an electrically insulating resin material into the mold afterthe conductive members are arranged therein so that the conductivemembers and the resin material are integrally molded to form a basemember having a semiconductor element-mounting face and a circuitboard-mounting face opposite the semiconductor element-mounting face,said arranging of the conductive members comprising orienting theconductive members in the mold so that the conductive members aresubstantially orthogonal to the semiconductor element-mounting face andthe circuit board-mounting face and extend linearly through an interiorof the base member between the semiconductor element-mounting face andthe circuit board-mounting face, said injecting comprising injecting theresin material in an axial direction parallel to the longitudinal axesof the conductive members through at least two injection openingsarranged symmetrically around each of the conductive members; mountingand electrically connecting a semiconductor element to the semiconductorelement-mounting face by flip-chip mounting; and mounting andelectrically connecting the circuit board-mounting face to a circuitboard.
 2. The method of claim 1, wherein said injecting comprisesinjecting the resin material in an axial direction parallel to thelongitudinal axes of the conductive members through the injectionopenings formed in an end of the mold closest to and supporting a firstend of each of the conductive members.
 3. A method of manufacturing asemiconductor element-mounting board, comprising: arranging a pluralityof conductive members in a mold; injecting an electrically insulatingresin material into the mold after the conductive members are arrangedtherein so that the conductive members and the resin material areintegrally molded to form a base member having a semiconductorelement-mounting face and a circuit board-mounting face opposite thesemiconductor element-mounting face, said arranging of the conductivemembers comprising orienting the conductive members in the mold so thatthe conductive members are substantially orthogonal to the semiconductorelement-mounting face and the circuit board-mounting face and extendlinearly through an interior of the base member between thesemiconductor element-mounting face and the circuit board-mounting face,said injecting comprising injecting the resin material in an axialdirection parallel to the longitudinal axes of the conductive membersthrough at least two injection openings arranged symmetrically withrespect to the conductive members, wherein the mold includes a firstholding plate for holding a first axial end of each of the conductivemembers, the injection openings being formed in the first holding plate,includes a second holding plate for holding a second axial end of eachof the conductive members and being operable to move in the axialdirection, and includes a pressure regulation mechanism for biasing thesecond holding plate in the axial direction in response to a compressionor extension of the conductive members due to said injection of theresin material; during said injecting of the resin material, moving thesecond holding plate in the axial direction using the pressureregulation mechanism in response to the compression/extension of theconductive members due to said injection of the resin material, therebyrestricting bends in the conductive members; mounting and electricallyconnecting a semiconductor element to the semiconductor element-mountingface by flip-chip mounting; and mounting and electrically connecting thecircuit board-mounting face to a circuit board.
 4. A method ofmanufacturing a semiconductor element-mounting board, comprising:arranging a plurality of conductive members in a mold; injecting anelectrically insulating resin material into the mold after theconductive members are arranged therein so that the conductive membersand the resin material are integrally molded to form a base memberhaving a semiconductor element-mounting face and a circuitboard-mounting face opposite the semiconductor element-mounting face,said arranging of the conductive members comprising orienting theconductive members in the mold so that the conductive members aresubstantially orthogonal to the semiconductor element-mounting face andthe circuit board-mounting face and extend linearly through an interiorof the base member between the semiconductor element-mounting face andthe circuit board-mounting face; after said injecting of the resinmaterial, forming a projecting portion of the conductive memberprojecting from the circuit board-mounting face of the base member, saidforming of the projecting portion including: leveling the base memberincluding the conductive members so that a thickness of the base memberis equal to a length of each of the conductive members; and after saidleveling, removing only a portion of the resin material of the basemember in a thickness direction of base member; plastically deformingthe projecting portion so as to form a land to be connected to a circuitboard; mounting and electrically connecting a semiconductor element tothe semiconductor element-mounting face by flip-chip mounting; andmounting and electrically connecting the circuit board-mounting face toa circuit board.
 5. The method of claim 4, wherein said removing of theportion of the resin material comprises one of wet etching, dry etching,sandblasting, and machining.